APPLICATION OF NUCLEIC ACID SEQUENCE‐BASED AMPLIFICATION FOR THE DETECTION OF VIABLE FOODBORNE PATHOGENS: PROGRESS AND CHALLENGES

Abstract

ABSTRACT Nucleic acid sequence‐based amplification (NASBA) is a sensitive transcription‐based amplification system that uses a battery of three enzymes (avian myeloblastosis virus reverse transcriptase, RNase H and T7 RNA polymerase) leading to a main amplification product of single‐stranded RNA, and is specifically designed for the specific detection of RNA. NASBA is an established diagnostic tool in clinical use, with a theoretically bigger analytical sensitivity than reverse transcription‐polymerase chain reaction (RT‐PCR) for pathogen detection, but is not progressing toward implementation in food analysis. This is unfortunate, because it has a potential for detection of viable cells through selective amplification of messenger RNA, even in a background of genomic DNA, which PCR does not possess. However, in some instances, an unexpected amplification of genomic DNA has been observed using the NASBA technique. The availability of methods for rapid, sensitive and selective detection of viable microbial pathogens in foods is a goal worth pursuing, and a developmental effort to explore and capitalize on NASBA's potential in this regard could be worthwhile. We review in this work the current status and the future application of this technique in food microbiology diagnostics.